Electric switch



Jan. 3-, 1939. R. F. SAMBLESON ELECTRIC SWITCH Original Filed Nov. 15, 1935 Inventor:

v Robert F. Samble son,

19 W4: CW

Attorney Patented Jan. 3, 1939 UNITED STATES ELECTRIC SWITCH Robert F. Sambleson, Bridgeport, Conn., assignor to General Electric Company, a corporation of New York Original application November 15, 1935, Serial No.

49.931. Divided and this application January 15, 1938, Serial No. 185,175

12 Claims.

This application is a division of my copending application, Serial No. 49,931, filed Nov. 15, 1935, which is assigned to the same assignee as the present application.

The present invention relates to electric switches of the type having liquid contact circuit-closers for controlling the fiow of current.

The object of my invention is to provide an improved construction and arrangement in a switch ofthis type.

In the accompanying drawing, Fig. 1 is a sectional side elevation of a switch embodying my invention; Fig.2 is a sectional view taken on line 22 ofFig. 1; and Fig. 3 is a diagrammatic view showing the construction and operation of a the liquid contact circuit closer.

Referring to the drawing, I have illustrated my invention using a liquid contact circuit closer having a pair of cup-shaped metal terminals I 'which are separated by an insulating diaphragm 2 of refractory material, such as a ceramic material. The edges of the terminals are sealed by a bead 3 of glass which also seals the junctions between the diaphragm and the terminals. With the space enclosed by the terminals is a suitable quantity of mercury 4 which forms the conduction medium between the terminals. In the manufacture of the circuit closer, the space en- 'closedby the terminals is evacuated and filled with hydrogen at a pressure of one or more atmospheres which increases the current interrupting capacity of the circuit closer. As shown by the-full lines in Fig. 3, the diaphragm 2 is provided with an opening 5 which is submerged in the mercury when the circuit closer is in the current conducting position. When the circuit closer is in the current interrupting position,

shown in dotted lines in Fig. 3, the opening 5 is in the mercury as the circuit closer is turned so that the opening 5 in the diaphragm approaches the dotted line position. The above described construction is illustrative of a type of I liquid contact circuit closer which is suitable for use in a switch embodying my invention.

50 For operating the liquid contact circuit closer,

plastic material having forked ends I which envelope more than half the periphery of the cir- I have'provided a handle 6 of molded thermofit within recesses 9 in the terminals of the circuit closer and on opposite sides thereof and prevent relative rotation between the handle and the circuit closer. The forked ends of the handle Y are snapped in place while hot and are held in place by the resilience of the forked ends. The gripping of the handle is increased by the shrinking of the material of the handle upon cooling so that after the handle has cooled, the circuit closer is tightly gripped by the handle. As shown in Fig. 2, the handle is shaped to conform with the outer surface of the circuit closer and is provided with a groove In which fits over the bead 3 and prevents sidewise displacement of the handle relative to the circuit closer.

The circuit closer is mounted within a housing v H of molded insulating material having side walls l2 in which are molded tubular inserts or binding posts 13. On the inner ends of these inserts are fixed contacts l4 having a plurality of fiexible contact arms l5. In the-outer end of the inserts are threaded binding screws l6 which clamp the line conductors to the inserts. The circuit closer-is assembled in the housing by sliding between the contacts 14. In this position the flexible contact fingers l5 frictionally engage the outer surface of the terminals I and conduct electricity to the terminals. Since a plurality of spring contact fingers l5 are provided, the contact fingers align'themselves with the surfaces of the, terminalsand provide good electrical contact. It is also apparent that this construction permits rotation of. the liquid contact switch about its axis. The wiping action between the terminals and the contacts tends to prevent increased contact resistance.

At the bottom of the housing is a spring strip ll provided with projections I 8 which slidably engage the periphery of the circuit closer at angularly spaced points and also having its ends l9 slidably carried in slots in the bottom wall of the housing. The projections l8 provide supports for the circuit closer and are also adapted I to engage a notch 2| formed in the periphery of the glass bead 3, and thereby to hold the circuit closer resiliently in a fixed position. The circuit closer is held within the housing ll and against the projections It by two curved spring strips 22 which engage the curved surfaces 23 of the handle on either side of the handle. As shown in Fig. 2, the edges of the spring strips 22 engage the handle in the housing. The spring strips 22 are riveted to a support or mounting strap 24 which is secured to the top of the housing ll the sides of the handle 6 and assist in centering by screws threaded into inserts 26.. The mounting strap is adaptedto be secured to an outlet box to mount the switch therein.

In the assembly of the switch, the handle 6 is secured to the liquid contact circuit closer and the contacts H are secured to the inner end of the inserts ii in the side walls of the housing. The ends IQ of the spring strip II are then placed in the slots 20 in the bottom wall of the housing, and thewcircuit closer is inserted in the housing so that the bottom of the glass bead 3 engages the projections it of the spring strip i1 and the terminals l engage the contacts it. The mounting strap 24 is then secured to the top of the housing by the screws 25, thereby holding the circuit closer in place.

In the use of the switch, the switch is mounted in an outlet box by means of the mounting strap 24. Due to the locationof the opening 5 in the diaphragm 2, the right-hand end of the mounting strap 24 should beat the top of the outlet box. When so mounted, vertical movement of the handle 8 causes the circuit closerto be rotated about its axis. When the handle is in the raised position, shown in full lines on Fig. 3, the opening 5 in the diaphragm 2 is submerged in the mercury, and an electriccircuit is completed through the mercury between the terminals I. When the handle is in the lowered position, as shown in dotted lines in Fig. 3, the opening 5 is raised out of the mercury, and the circuit between the terminals I is broken. The handle is resiliently held in either the raised or the lowered positions by the 40 What I claim as new and desire to secure by Letters Patent of the United States is:

1. In an electric switch, a housing having spaced side walls, binding postsfixed in the housing side walls the outer ends being accessible for connection from the outside of the housing and the inner ends extending within the housing, opposed spring contacts carried by the inner ends of said binding posts, a liquid contact circuit closer between said contacts having an enclosure including opposed cup-shaped terminals, said terminals frictionally engaging said contacts whereby the terminals are rotatable on the contacts, and means supporting the circuit closer for rotation on said contacts. I

2. In' an electric switch, a cylindrical liquid contact circuit closer operable by rotatipn about its axis, a housing, spring means at the bottom or said housing, means secured to said housing andhaving a curvedportion slidably engaging less than half of the periphery of said circuit closer tor hoidingsaid circuit closer against'said spring means and providing a seat in which the circuit closer is'rotatable, said spring means and said circuit closer being provided with interiitting portions whereby said circuit closer is resiliently held in a fixed position.

3. In an electric switch, a cylindrical liquid contact circuit closer operable by rotation about its axis, a curved member slidably engaging less than half of the periphery of the circuit closer on one side of its axis and providing a seat in which it is rotatable, and resilient means irictionally en gaging the periphery of the circuit closer on the opposite side oi its axis and on each side of an axis passing through thecenter' of said curved 1 said notch for resiliently holding the circuit closer in a fixed position.

member, said circuit closer being held for rotation about, its axis between said resilient means and said curved member.

4. In an electric switch, a cylindrical liquid cmtact circuit closer operable by rotation about its axis, a housing, a curved member slidably engaging less than half of the periphery of the circuit closer on one side of its axis and providing a seat in which it is rotatable, and a spring strip having an and slidable in saidhousing and having portions engaging the periphery oi the circuit closer on the opposite side of its axis and on each side of an axis passing through the center oi said curved member, said circuit closer being held for rotation about its axis between said spring strip and said curved member.

5.. In an electric switch, a cylindrical liquid contact circuit closer operable by rotation about its axis, a pair of supports slidably engaging the periphery of the circuit closer at angularly spaced Q points on one side of its axis, and means holding said circuit closer against said supports for supporting said circuit closer for rotation about its axis, and means for rotating the circuit closer on said, supports.

6. In an electric switch, a cylindrical liquid contact circuit closer operable by rotation about its axis, a spring strip having portions slidably engaging the periphery of said circuit closer on one side of its axis at angularly spaced points, i

means holding said circuit closer against said portions or the spring. strip whereby said circuit closer is supported for rotation about its axis,

and means for rotating the circuit closer about its 7. In an electric switch, a cylindrical liquid contact circuit closer operable by rotation about its axis, a housing. a spring strip having an end slidable in said housing and having portions slidably engaging the periphery of said circuit closer on one side oiits axis at angularly spaced points. and means holding said circuit closer against said spring strip whereby said circuit closer is supported for rotation about its axis, said spring strip and said circuit closer having detent portions whereby thecircuit closer is resiliently held in position.

8'. In an electric switch, a cylindrical liquid contact circuit closer operable by rotation about its axis, a housing for said circuit closer. a pair of spaced supports on the bottom oi said housing slidably engaging the periphery oi said circuit. closer at angularly spaced points, and a strap secured to said housing and engaging the top or said circuit closer for holding said circuit closer against said supports whereby said circuit closer .is supported for rotation about its axis.

: sealing material, means engaging said terminals for supporting the circuit closer for rotation, a notch in said head, and spring means engaging 10. In an electric switch, a cylindrical liquid contact circuit closer operable by rotation about its axis,'means for rotatably supporting the circuit closer includingan arcuate seat slidably engaging less than hali oi the periphery oi the circuit closer, resilient means for holding the circuit closer against said seat, and means for rotating the circuit closer on said seat.

11. In an electric switch, a cylindrical liquid 1 12. In an electric switch, a cylindrical liquid contact circuit closer operable by rotation about its axis, a seat slidably engaging less than half of the periphery of the circuit closer on one side of its axis, and means holding the circuit closer 5 against said seat whereby the circuit closer is supported for rotation. I

ROBERT F. SAMBLESON. 

